How Phone Batteries Degrade

All phone batteries are lithium-ion. Every charge cycle — from low to full — permanently reduces the battery’s maximum capacity by a tiny amount. After 300 to 500 cycles (roughly 1 to 2 years of daily charging), most batteries are at 80% of their original capacity or below.

At 80% capacity, a phone that originally lasted 12 hours now lasts around 9 to 10 hours. At 70%, you’re looking at 8 hours. The degradation accelerates as the battery ages further.

6 Reasons Your Battery Drains Fast

1. Natural degradation

The most common cause. Every battery has a finite lifespan. If your phone is more than 18 months old and draining noticeably faster, degradation is the most likely cause.

2. Screen brightness too high

The display is the single biggest battery drain on any phone. Auto-brightness helps, but many people override it and run at maximum brightness all day — especially in Singapore’s bright outdoor conditions.

3. Background app refresh

Apps running in the background constantly checking for updates, messages and location data drain battery silently. Check which apps are using the most background battery and restrict the ones you don’t need.

4. Poor signal areas

When your phone is in a weak signal area — basement carparks, certain MRT stations, older buildings — it constantly boosts its radio power trying to maintain a connection. This drains battery 2 to 3 times faster than normal.

5. Extreme temperatures

Singapore’s heat accelerates battery degradation over time and reduces capacity temporarily in the short term. Leaving your phone in direct sunlight or a hot car regularly will age the battery significantly faster.

6. Swollen battery

A swollen battery has undergone a chemical reaction that causes it to physically expand. Capacity drops sharply and the phone may shut off randomly. This is a safety issue — a swollen battery needs immediate replacement.

When Should You Replace the Battery?

• iPhone battery health is below 80%
• Phone doesn’t last through a full working day on a single charge
• Battery percentage drops suddenly — e.g. from 30% to 5% with no warning
• Phone shuts off before reaching 0%
• Phone gets unusually warm during normal use or charging
• Any sign of physical swelling

Tips to Make Your Battery Last Longer

Keep charge between 20% and 80%. Lithium-ion batteries degrade faster when regularly charged to 100% or run down to 0%. Most phones now have an optimised charging setting that slows charging above 80% overnight — turn it on.

Avoid wireless charging for daily use. Wireless charging generates more heat than wired, which accelerates battery degradation over time. Use wired charging for daily top-ups and wireless occasionally.

Use Low Power Mode proactively. On iPhone, Low Power Mode reduces background activity significantly. Turning it on at 50% instead of waiting for the 20% warning extends your daily battery life noticeably.

Turn off Always-On Display. On Samsung and other Android phones with always-on displays, this feature alone can account for 10 to 15% of daily battery drain.

Common Questions

How long should a phone battery last before needing replacement?

On average, 18 to 24 months of daily use before noticeable degradation. Heavy users who charge twice daily may see it sooner. Light users who charge once every two days may get 3 years or more.

Will replacing the battery make my phone feel like new?

If battery degradation is the main issue, yes — significantly. A new battery restores full capacity and eliminates unexpected shutdowns and percentage jumps. Combined with a software update, many customers tell us their phone feels noticeably faster after a battery replacement.

Is it worth replacing the battery on an older phone?

Generally yes, if the rest of the phone works well. A battery replacement is far cheaper than a new phone and extends the useful life of your device by 1 to 2 years. The calculation changes if your phone is very old and slow due to an outdated processor.

How long does a battery replacement take?

30 to 45 minutes at any of our 4 outlets. Walk in — no appointment needed.